Miracast: Everything to know about mirroring Android

By Sharon Vaknin2013-09-24

Get to know the wireless tech that lets you duplicate your Android device's screen on your TV so you can watch HD movies, play music, or supersize your favorite apps.

Every so often, another device is touted as supporting "Miracast." Fighting its way into the mainstream, Miracast is a killer feature poised to wipe out other video streaming standards in a very fragmented
Android market.

Acting like a wireless HDMI cable, Miracast mirrors your Android device onto your TV screen in high definition and with audio. Once Miracast is enabled, everything -- from the general interface, to apps and videos -- is duplicated on the big screen without the burden of a cable connecting the two devices.

Its differentiating quality? It doesn't rely on your home's Wi-Fi network. But it's not magic -- let's lift the hood to see how Miracast works.

Under the hood

Seasoned Android users' ears will perk up when they hear that Miracast is built on the much-ignored Wi-Fi Direct technology. Wi-Fi Direct, first introduced in Android 4.0, allows a user to create a private (ad-hoc) network that allows other users to connect and share files. The technology never quite caught on in the mainstream, but it did pave the way for Miracast.

With Wi-Fi Direct as the foundation, it makes sense that Miracast doesn't need to rely on your home's network. Instead, it creates is own. For instance, your television creates the ad-hoc network, which is then discovered by your Android phone or
tablet. Once the two devices are paired, data can flow freely between them.

When it comes to what you can stream to your TV, the options are endless. Miracast employs the H.264 codec to mirror videos in 1080p and 5.1 surround sound audio. Even copyright-protected materials like DVDs and music can be mirrored, thanks to a DRM layer.

Wait, is this like Chromecast?

I am so glad you asked. No, Miracast is absolutely not like Chromecast. Here's why.

With Miracast, your TV (or Miracast dongle) is dependent on your Android device the entire time the devices are paired. If your Android goes to sleep, your TV's screen blacks out, too. This co-dependency is both a great advantage and a tragic pitfall for Miracast (think battery life).

Chromecast, however, only relies on the mobile device for a moment during the initial setup. Once the Chromecast receiver knows what content it needs to play, your mobile device holds none of the load. In which case you're free to multitask, lock your device, or queue up the next video.

For the same reason, Chromecast is not nearly as dynamic as Miracast -- it only works with compatible video and music apps and will not play DRM-protected content on your device. And mirroring? Fuggetaboutit. Chromecast let's you mirror you Chrome browser (in beta), but that's it.

How to use Miracast

To make use of Miracast, you'll need two things: a Miracast-compatible Android device, and a Miracast TV or dongle.

Setting up wireless mirroring on the Nexus 7.

The Android part is easy. If your device runs Android 4.2 or later, you most likely have Miracast, also known as the "Wireless display" feature.

Now you'll need to set up your Miracast receiver. Though the tech is relatively new, a number of TV manufacturers like Sony, LG, and Panasonic, are integrating Miracast into their televisions. But, unless you purchased a TV in the last year, it's probably not Miracast-ready. Instead, you'll need a dongle.

Head to Amazon and you'll see a number of Miracast dongles. Even Best Buy creates one under its house brand, Rocketfish. Most of these dongles land in the $40-$60 range, and are really only designed to do one thing: mirror your Android device.

At CNET, we tested Netgear's Push2TV dongle, which was mostly reliable, save for a few laggy moments and stuttering playback. Overall, though, it did the job. You can view a complete list of Miracast-ready TVs, dongles, and set-top boxes here.

Turn the Wireless display feature on, and wait a moment while the device looks for your Miracast dongle or TV. When it appears in the list, tap to connect, and a few moments later, you'll see your Android device duplicated on the big screen.

Now you're free to fire up a playlist, watch a movie in 1080p, or let your friends watch you play Candy Crush Saga on the big screen. Just be mindful that although the brightness on your device doesn't affect that of the TV, locking your Android will also black out your TV.

So, if you're watching a movie, be sure to hook your Android up to its charger.

The verdict

Though Miracast is easily the best all-in-one solution for getting Android on the big screen, the technology still has room for growth. The lack of multitasking is the biggest disappointment, arresting your Android device while it actively generates content for the Miracast receiver. That, however, is already changing. The LG G2, the Sony Xperia Z, and the Optimus G Pro are the first phones to allow Miracast multitasking, letting you mirror your screen while you continue browsing on your phone.

But even with increased compatibility, Miracast needs help. Sometimes laggy video and occasional difficulty establishing a connection between the Android device and the receiver make an otherwise enjoyable experience frustrating. Still, the ability to mirror anything on your Android, and the convenience of a wireless connection could make Miracast a worthy investment.